Case Study of Y Knitting Mills Ltd.

Survey of Bangladesh Textile industry to Up-date Database/MIS and to Assess the Requirement of Textile Technologists at Different Levels

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Prepared by

Green University of Bangladesh

Introduction:

The case study of Y Knitting Mills Ltd. is situated at Valuka, Mymensing. In respect of technical point of views (machines, raw materials, production planning, sequence and operation, maintenance, utility service, store and inventory control, cost analysis), it is a very good graded Knit Dyeing Mill and a strong base of financial aspect and marketing activities, this Mill is 100% export oriented and running up to now with profit.

A brief description of X1 Weaving Mills Ltd:

1. Name of the Mill                            : Y Knitting Mills Ltd

2. Nature of the Ownership              : Private Limited Company

3. Year of Establishment                  : 2005

4. Authorized Capital                       : Tk: 39.07

5.  Paid-up Capital                            : Tk: ?

6. Land Area                                     : 5 Bighas

7. Physical Structure                          : Pucca + Pre-Fabricated

8. Type or Nature of Mill                 : Knitting

9. Machine and Equipments, Capacity and Capacity Utilization:

SlNo.	Name of the Machine	Origin and Year of Purchase	No. of Machine	Installed Capacity Kg/Day	Target Production Kg/Day	Capacity Utilization (%)
1	Circular Knitting	Mayer &Cie Germany	24	10368	9331	90
2	Dyeing Machine	Origio, Itally	20	8400	7560	90

10. Stock Position and Volume of Shortfall (July 2007-December 2007)

Types of Stock	Stock (Kg)	Value of Stock (Tk)
Yarn	45000	5,40,0000

There was no shortage of raw material in the mill during July 2007 to December 2007.

11. Last Three Years Production (in Kg)

Sl. No.	Product	2005-06	2006-07	2007 (July07-Dec 07)
1	Cotton Fabric	85,00,000 yds	95,00,000 yds	51,00,000 yds
2	Total	85,00,000 yds	95,00,000 yds	51,00,000 yds

Production history of last two years.

12. Production and Shortfall During July 2007-December 2007

SlNo.	Name of the Machine	No. of Machine	Installed Capacity Yds/Day	Target Production Yds/Day	CapacityUtilizatio Yds/Day	Shortfall
1	Ball Warping	3	72000	65000	33000	49%
2	Dyeing Machine	1	72000	65000	33000	49%
3	Long Chain Beamer	8	72000	65000	33000	49%
4	Loom	100	65000	60000	33000	45%
5	Sizing	1	60000	58000	33000	43%

13. Calculation of Sale Price During July 2007-December 2007

Products	Cost of Production	Sale Price	Total Revenue (Tk)	Profit (Tk)
Woven Fabric	127.65 Tk/Yd	140.42 Tk/Yd	65,10,15,000	6,40,05,000

14. Reason of Production Shortfall During July 2007-December 2007

Sl. No.	Reason of Production	Shortfall During The Quarter
1	Electricity Failure	X
2	Shortage of Raw Material	X
3	Shortage of Working Capital	X
4	Lack of Proper Planning	X
5	Misleading Lead Time/Procurement Time	X
6	Lack f Spare and Accessories	X
7	Strike/Unrest	X
8	Natural Disaster	X
9	Shortage of Skilled Manpower	√

From the above table it is clear that shortfall of production is only for shortage of skilled manpower. It is assumed that huge 50% production shortfall occurs due to shortage of Textile Technologists.

15. Cost of Good Sold

CHART OF COST OF THE FACTORY

16. Number of Shifts, Working Hours and Days During July 2007-December 2007

No. of Shifts/Day	Total No. of Shifts During July 2007-December 2007	Total No. of Days During July 2007-December 2007	Total No. of Working Hours During the Quarter
2	312	156	2496

17. Raw Material/Input Used During July 2007-December 2007

      2808000 Kg

18. Wastages in terms of % (During the Quarter Ended Decmber 2007)

Yarn	Fabric	Total
0.5%	0.5%	1%

19. Investment:

Fixed Assets in Tk		Working Capital in Tk
Original Value	Present Depreciated Value	In Cost Price as on 31stDecember 2007
39.01 Cores		2.5 Cores

20. Wages and Salaries (Tk) as in December 2007

Period	Officers and Staffs	Labour
December 2007	13,50,000.00	16,50,000.00

21. Manpower as on 31^st December 2007:

Level of Skill ness	Education	Requirement	Existing	Shortfall	Shortage (%)
Managerial Level	B. Sc/M.Sc./MBA in Textile Engg.	1	0	0	100%
High Skill/Expertise Level	B. Sc in Textile Engineering	6	5	1	17%
Moderate Skill Level	Diploma in Textile Engineering	15	10	5	33%
Specialized Skill Level	Trade Course	25	15	10	40%
Skilled /Unskilled Labour	Skilled by Experience	390	410	20	(+5)%

From the above table we have a clear idea about the present condition of overall situation of different mills and we can simulate this case in real/practical fields forenginners and technicians in the following ways.

Figure: Requirement of Textile Engineers and Technologists at Different Level.

22. Product Diversification Matching with the Need of RMG Sector and Quality

      Improvement

Sub-Sector	Existing Supply/Yr of Products to RMG Sector		Scope of Additional Production and Supply to RMG Sector		Scope for Improvement of the Product
	Products	Quantity	Yes/No	How?	Yes/No	How?
Weaving	Fabric	99,00,000Yds	Yes	By Increasing Skilled Manpower	Yes	By Increasing Skilled Manpower

23. Conclusion:

From the above study, it is clear that the reason of shortfall of product is only due to shortage of Textile Technologists/Engineers. We have seen that there is about 40% shortage of Textile Technologists/Engineers at different levels. It is possible to achieve 100% target production and also quality by recruiting Textile Technologists/Engineers. So it is essential to appoint Textile Technologists/Engineers at different levels in all the textile mills within short time to face the challenge of 21^st century.

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Most common Textile Inspection System

Piece goods inspection system:

In 1955 ten points piece goods evaluation was approved by the textile distribution & national federation of textiles. This system assigns penalty points to each defect.

Ten points system:- Filling defects penalty
Warp defects                 Penalty                       Full width                    10 points

10-30 ̎                          10 points                   5 ̎ ½ the width:                    5 ″

5-10 ̎                                 5 ″                                1-5 ̎ :-                        3 ″

1-5 ̎                                   3 ″                           up to 1 ̎ :-                        1 ″

Up to 1 ̎ 1 ″

Under the ten point system, a piece is graded a fixed if the total penalty point do not exceed the total yardage of the piece. A piece is graded a ‘second” if the total penalty points exceed the total yardage of the piece.

Four points system:

It is widely used in textiles. It is simple & easy to under stand. Inspection is done about 10% of the product in the shipment. This system has been applied by AAMA (American Apparel manufacturing association).

The four points system classifies classified defects as follow:

Size of defects                                             Penalty

3 ̎ or less                                                     1 point

Over 3 ̎not over 6 ̎                                       2 ″

Over 6 ̎but not over 9 ̎                                 3 ″

Over 9 ̎                                                       4 ″

A maximum 4 points is changed for one leniaroooo yard

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Fabric faults produced during weaving & knitting production

Weaving fault:
Warp way defect:
I. Warp stitching : Occurred due to want of interlacement between warp & weft yarn which happen:
   Ø If the warp threads of one shed goes to another.
   Ø Faulty dobby or jacquard mechanism.
   Ø Warp yarn if loose.
   Ø Height of the harness card if not equal.
   Ø Warp is not properly sized.

a) Long float: causes due to
   Ø If the warp yarn does not take part in interlacement.
   Ø Tappet is not properly tied.
   Ø Peg if dobby displaced.
   Ø Jacquard harness or cord cutting if defective.
   Ø Worn out Reed if used.

b) Wrong warp threads: due to drafting & lifting.
Missing warp: causes due to:
   Ø Wrong denting.
   Ø Broken warp yarn in the beam.
   Ø Out of order warp stop motion.

d) Double warp: warp way marks on the fabric due to:
   Ø Wrong reed count used.
   Ø Wrong denting in the reed.

e) Loose warp: Causes due to
   Ø Loose warp exist on the beam in loop form.
   Ø Yarn tension in the dropper.
   Ø Size picks up unequal.

f) Knot in the warp yarn: If there are any knots in warp yarns.

g) Selvedge effect: Causes due to :
   Ø If the body and selvedge warp yarns tension is unequal.
   Ø If the reed space is greater but the width of the fabric is les.
   Ø Sharp temple ring spikes.

h) Weft cut at the selvedge: due to
   Ø Absent of weft yarn in the selvedge
   Ø Defective ring temple.
   Ø If the temple not properly set.

i) Temple mark: Mark on the selvedge of the fabric due to: light fabric if course temple is used.

Weft way fault:
1. Miss pick or broken pick:- Causes Due to
   Ø Broken pick.
   Ø Yarn of pirnoooo is finish.
   Ø If weft yarn breaks at the middle.
   Ø Picking much uniform occurred by empty shuttle.

2. Broken design: If the lifting mechanism is defective.

3. Thick & thin place which is called bar on the fabric.

4. Shuttle mark:
   Ø Shuttle flies.
   Ø Shuttle box is not properly set.

Defective of knitted goods to be unspected:

1. Broken ends: If the yarn breaks, holes create in the fabric.
   Ø During loop formation if the yarn previously broken in the needle.

2. Drop stitch:
   Ø Due to defective needle.
   Ø Yarn feeder not properly set.
   Ø Wrong take up mechanism.
   Ø Stitching tension if not proper.

3. Slugging.
   Ø Only occurs in continuous filament yarn.
   Ø Occurs due to mechanical strain in the next process stages.

4. Tuck & doable stitch: Occurs due to badly oooo or knitted loop. It results the formation small brads or thick & thin places in large ascoooo.

5. Bunching up: Visible knots in the fabric eyes known as beads.

6. Vertical stripe: Vertically shown streaks on the Wales which causes due to:
   Ø Gauge is not done according to count.
   Ø Stitch size.
   Ø Course density.

7. Horizontal stripe: unevenness along the course direction.
   Ø Yarn feeder if not properly set.
   Ø Tension if not uniform.

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AQL | Acceptable Quality Limits or Level

Major concept of Acceptable Quality Limit or Level:
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It is the allowable percent defective in a lot. This is introduced according to American military Standard of product inspection rules. There are generally 6 AQL used in textile which are as follows:- 1%,1.5%,2.5%,4%,6.5%,and 10%. Among them 2.5%,4%,6.5% and 10% are widely used and accepted according to price and type of garments.

Uses of AQL: In this system, sample is selected statistical method by using random sampling technique from a lot. After proper inspection along with the test results, the decision is taken, whether the lot will be accepted or rejected. Now a days this system is widely used in garments sector before the delivery. Although it is used from raw material to finished product also.

Acceptable sampling system consists of five parts:
1. Lot size
2. Sample size
3. AQL
4. Acceptable number
5. Reject number

Quality Inspection of factories:
According to JIS, Inspection is defined as “ to measure goods by some methods and by comparison with the results obtained against the criteria to judge whether the individual goods are defective or not

In textile factories the fabrics are inspected at the grey state, after pretreatment, coloration and finishing. After inspection the fabrics are classified according to their quality. Therefore fabrics are inspected to meet the requirements of the customers.

The fabrics are categorized in the following way depending upon the faults:

I. Fresh or First quality: Fabrics, hemming major, minor faults according to buyer specification and requirements.
II. Short length or two parts: It is a piece of cloth having a shorter length( More then 50 cm ). Jar parts become equal to fresh quality. Generally buyers gives (3-5)% discount value for the short length.
III. Seconds: Fabrics containing much objectionable minor defects and (8-15)% discount is allowed.
IV. Fents: Cut pieces of fabric measuring 90 cm or more but less than 150 cm lengths. For fents trade discount is (15-30) %.
V. Rags: Cut pieces of fabric measuring 25 c or more but less than 90 cm. This categories are sold by weight and realization is only about 50% of fresh fabric.
VI. Chilly: These are pieces of 25 cm length fabric less than this. These fabrics are bought & sold and trade discount generally given is ( 50-80).

Quality Parameters of Woven Fabrics to be inspected are as follows:

(1) Dimensional characteristics:
a) Length b) Width c) Thickness

(2) Weight of fabric:
a) Weight/unit area b) Weight/unit length

(3) Fabric strength & Elongation
a) Tensile strength b) Tearing c) Bursting

(4) Threads/inch:
a) Ends/inch
b) Picks/inch

(5) Yarn count
a) Warp count
b) Weft count

(6) Crimp
a) Warp count
b) Weft count

(7) Handle

a) Stiffness
b) Drape

(8) Crease resistance & crease recovery

(9) Air permeability

(10) Abrasion resistance and pilling.

(11) Shrinkages/Dimensional stability

(12) Different fastness properties:-
a) Washing fastness
b) Light fastness
c) Perspiration fastness
d) Rubbing

(13) Flameability

(14) Water resistance or absorption power

(15) Design of fabric

(16) Appearance of fabric

Quality parameters for knitted fabric to be inspected:

1. Strength & elongation
2. Course density
3. Wales density
4. Loop length
5. Deformation
6. GSM
7. Yarn count
8. Design

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Bonded Fabric

Bonded fabric is a combined structure of fabric that is being created by joining two set of fabric. This attachment of two fabrics can be made with adhesive or thin bonding fabric with low melting point without any major changes of finished fabric thickness. Here a face or shell fabric is joined with backing fabric. Artificial leather products can be a good example of this type of fabric. Bonded fabric also used in design purposes and fabric stabilization.

An aqueous acrylic adhesive is used for joining bonded fabric. A latex adhesive such as, acrylate, a vinyl chloride or vinyl acetate or thermosetting resin also being used for this purpose. This bonding strength between these two layer fabrics is the main thing where the end uses of the finished product depends on.

Fabric Bonding Procedure:
There are two common methods for attaching fabric to fabric.
1. Wet adhesive method
2. Flame foam method

Wet adhesive method:
· An adhesive liquid is applied to the back of the face fabric.
· Face fabric is set on backing fabric and passed together between the heated rollers.
· Thus, the heat fixes the adhesive between two fabrics and makes the bonded fabric.

Flame foam method:
· Here, a thin layer of polyurethane foam is used to attach two set of fabrics
· First, polyurethane foam is melted a little by passing it over a fire/heat.
· Then this melted foam is set between two layers of fabric just like a sandwich.
· After that, when the foam got dries, it attach the two layers of fabric.

Actually the foam in the bonded fabric is so thin (around 0.010 inch). That why, It doesn’t make any significant changes on the thickness of the finished fabric. By this method fabric may got stiffer than the wet-adhesive method. Sometime foam may appear of the surface of the fabric. That’s why it is not better not to use this method with open-weave fabrics.

Advantages
· This bonded fabric is much cheaper in price
· This fabric is machine washable
· Fabric doesn’t crease easily

Crimp based on warp and weft yarn on fabric

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CRIMP
When warp and weft yarns are interlaced in a fabric they follow a WAVE or CORRUGATED configuration, the plane of the weave being substantially perpendicular to that of the fabric. This WAVINESS OF YARN is called CRIMP of yarn and is expressed quantitatively either as a fraction, c or as a percentage, c per cent:

c = (Ly - Lf)/Lf; and, c per cent = (Ly – Lf) x 100/Lf

Where Ly = the un crimped length of the yarn, and, Lf = its extent in the fabric.

The expression c = (Ly – Lf) / Lf may be written as:

c = Ly / (Lf - 1), from which

(1 + c) = Ly / Lf;

where (1 + c) is called the crimp ratio. It is useful in fabric calculations.

MATH: Calculate the length of warp required to weave 160 yds. of cloth if the warp crimp is 12 percent.

We know,
Lf = 160 yd. and c1 percent = 12; so c1 = 0.12, where c1 is fractional warp crimp, and

Ly = Lf (1 + c) = 160 x 1.12 = 179.2 yd.

So, to prepare 160 yds of fabric 179.2 yds of warp is required.

MATH: What length of cloth can be woven from 800 yds of warp if the crimp is 8 percent?

We know
Ly = 800 Yd., and c1 percent = 8, so c1 = 0.08; where c1 is fractional warp crimp, and

Lf =Ly/(1+c) = 800/1.08 = 740.8 yds.

So, 800 yds. of warp will weave 740.8 yd of cloth.

When the shuttle inserts the weft in the open shed, the weft is un crimped, and each pick has a length Ly, which is equal to the width occupied by the warp in the reed. This is called the reed width. When it is beaten up by the reed and incorporated into the cloth at the cloth fell, the weft attempts to crimp under the scissors-like pressure exerted by the warp threads. At this stage, it is prevented from crimping freely by the temples, whose function is to hold out the cloth near the fell to reed width, so as to prevent excessive abrasion of the warp threads near each selvedge by the reed. As the cloth moves forward towards the breast beam, it leaves the temples and is free to contract to a length Lf, called loom-state width. The weft is now crimped. We have three variables, i) reed width, ii) the width of the loom-state cloth, and iii) the weft crimp in the loom-state cloth. If we know two of these variables, the third can be calculated as illustrated by the following examples.

MATH: Calculate the reed width required to give a cloth with a loom-state width of 38”, if the weft crimp in the loom-state cloth is known to be 6 percent.

We know
Lf = 38”, and c2 percent = 6; so c2 = 0.06, where c2 weft crimp, and

Ly = Lf (1 + c) = 38 x 1.06 = 40.28”

which is the required reed width.

MATH: Calculate the loom-state cloth width if the reed width is 60”, and the weft crimp is known to be 9 percent.

We know

Ly = 60” and c2 percent = 9; so c2 = 0.09, where c2 is weft crimp, and

Lf = Ly/ (1+c) = 60/1.09 = 55.05”

which is loom-state cloth width.

MATH: Calculate the weft crimp in the loom-state cloth if the reed width is 44” and the loom-state cloth width is 40”.

We know

Ly = 44”, and Lf = 40”.

Therefore (1+c) = Ly/Lf = 44/40 = 1.10, so c2 = 0.10 and c2 percent = 10

which is the weft crimp.

In any of the above examples we could substitute the width of the finished cloth for that of the loom-state cloth, provided that we also substitute the weft crimp in the finished cloth for that of the in the loom-state cloth. The calculation would be valid, if no unrecoverable shrinkage had occurred during finishing, but not, for example for a milled woolen cloth.

EFFECT OF CRIMP OF YARN ON FABRIC PROPERTIES
a) RESISTANCE TO ABRASION: With the increase of crimp %, the abrasion resistance will also increase
b) SHRINKAGE: With the increase of crimp %, shrinkage of fabric will decrease.
c) FABRIC BEHAVIOUR DURING TENSILETESTING: With the increase of crimp%, breaking load of fabric will also increase.
d) FABRIC COSTING: With the increase of crimp%, fabric costing will also increase. Because crimp decrease the length of yarn as a result more yarn will be needed for fabric manufacture in case of more crimp on yarn.
e) FAULTS IN FABRIC: If there is variation of crimp in the threads then the following faults may be found in fabric; A) Reduction in strength may occur, and B) Stripes will be seen in yarn dyed cotton fabric.
f) FABRIC DESIGN: To achieve satisfactory appearance and required shape in finished fabric control of crimp in warp and weft yarn is necessary..
g) FABRIC STIFFNESS: If crimp is increased then stiffness of fabric will decrease.
h) ABSORBENCY: With the increase of crimp % absorbency of the fabric will increase.
i) DIMENSIONAL STABILITY: Dimensional stability will decrease with the increase of crimp%.
j) FABRIC HANDLE: If crimp is increased then the fabric will be soft in handle.
k) DYE TAKE-UP: With the increase of crimp the take-up percentage of dye-uptake will also increase.

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